The present invention relates to a multi-path gearbox, and more particularly to a multi-path torque split gearbox for an aircraft.
A gearbox system transfers power from a gas turbine engine to a rotor or propeller of an aircraft. A typical system may direct power from several turbine engines to a single rotor or propeller. Since the rotational velocity of the rotor or propeller is significantly lower than the rotational velocity of the gas turbine engine, the gas turbine engine rotational velocity must be reduced by the gearbox system. In reducing the rotational velocity of the gas turbine engine output, torque is increased through a series of intermediate gear stages and shafts, before the final output drive is provided to the rotor or propeller.
One prior art system includes a number of gears arranged for providing split-torque paths. The torque normally carried by a single drive train path is carried by two drive train paths to thereby split the torque of the original drive train path. The combined weight of these two split-torque paths is less than the weight of the original single drive train path. While this prior art split torque system has managed to increase the horsepower-to-weight ratio in some situations, especially where total horsepower involved is substantial and where multiple input drive paths from different engines are present, this conventional approach still requires a relatively large volume system of relatively significant weight.
Many conventional and split-torque gearbox systems are somewhat heavy and voluminous due to unequal load sharing. Unequal load sharing results when the gearbox system does not consistently split the load. This requires each gear to be sized larger than optimal so as to assure adequate load capability even when the load may not be consistently split.
Furthermore, although effective, typical split torque gearbox systems are usually designed for a single aircraft platform due to the relatively large volume necessarily inherent in these conventional designs. Each aircraft platform must be designed to accommodate particular engine positions associated with the particular gearbox system.
Accordingly, it is desirable to provide a multi-path torque split gearbox system that is relatively uncomplicated and inexpensive to manufacture, has a reduced weight and packaging size, assures an even split of loads, includes independent redundant load paths, yet provides inherent adaptability to various aircraft platforms.